Turbine blades are the primary elements of wind turbines for converting wind energy into electrical energy. The blades have the cross-sectional profile of an airfoil such that, during operation, air flows over the blade producing a pressure difference between the sides. Consequently, a lift force, which is directed from a pressure side towards a suction side, acts on the blade. The lift force generates torque on the main rotor shaft, which is geared to a generator for producing electricity.
The turbine blades typically consist of an upper (suction side) shell and a lower (pressure side) shell that are bonded together at bond lines along the trailing and leading edges of the blade. The bond lines are generally formed by applying a suitable bonding paste or compound along the bond line at a minimum designed bond width between the shell members. The bond paste, however, tends to migrate well past the designed bond width and into the interior blade cavity, particularly along the trailing edge of the blade. This excess bond paste can add considerable weight to the blade and, thus, adversely affect blade efficiency and overall performance of the wind turbine. The excess bond paste can also break off and cause damage to interior structure and components during operation of the wind turbine.
Accordingly, the industry would benefit from an improved bond line configuration that reduces the amount of excess bond paste that migrates into the blade cavity, particularly along the trailing edge of the turbine blade.